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Diffstat (limited to 'drivers/mtd/devices')
-rw-r--r--drivers/mtd/devices/m25p80.c69
1 files changed, 40 insertions, 29 deletions
diff --git a/drivers/mtd/devices/m25p80.c b/drivers/mtd/devices/m25p80.c
index 47486fbd777..e6892851e81 100644
--- a/drivers/mtd/devices/m25p80.c
+++ b/drivers/mtd/devices/m25p80.c
@@ -709,6 +709,14 @@ static const struct spi_device_id *__devinit jedec_probe(struct spi_device *spi)
jedec = jedec << 8;
jedec |= id[2];
+ /*
+ * Some chips (like Numonyx M25P80) have JEDEC and non-JEDEC variants,
+ * which depend on technology process. Officially RDID command doesn't
+ * exist for non-JEDEC chips, but for compatibility they return ID 0.
+ */
+ if (jedec == 0)
+ return NULL;
+
ext_jedec = id[3] << 8 | id[4];
for (tmp = 0; tmp < ARRAY_SIZE(m25p_ids) - 1; tmp++) {
@@ -730,7 +738,7 @@ static const struct spi_device_id *__devinit jedec_probe(struct spi_device *spi)
*/
static int __devinit m25p_probe(struct spi_device *spi)
{
- const struct spi_device_id *id;
+ const struct spi_device_id *id = spi_get_device_id(spi);
struct flash_platform_data *data;
struct m25p *flash;
struct flash_info *info;
@@ -743,41 +751,44 @@ static int __devinit m25p_probe(struct spi_device *spi)
*/
data = spi->dev.platform_data;
if (data && data->type) {
+ const struct spi_device_id *plat_id;
+
for (i = 0; i < ARRAY_SIZE(m25p_ids) - 1; i++) {
- id = &m25p_ids[i];
- info = (void *)m25p_ids[i].driver_data;
- if (strcmp(data->type, id->name))
+ plat_id = &m25p_ids[i];
+ if (strcmp(data->type, plat_id->name))
continue;
break;
}
- /* unrecognized chip? */
- if (i == ARRAY_SIZE(m25p_ids) - 1) {
- DEBUG(MTD_DEBUG_LEVEL0, "%s: unrecognized id %s\n",
- dev_name(&spi->dev), data->type);
- info = NULL;
-
- /* recognized; is that chip really what's there? */
- } else if (info->jedec_id) {
- id = jedec_probe(spi);
-
- if (id != &m25p_ids[i]) {
- dev_warn(&spi->dev, "found %s, expected %s\n",
- id ? id->name : "UNKNOWN",
- m25p_ids[i].name);
- info = NULL;
- }
- }
- } else {
- id = jedec_probe(spi);
- if (!id)
- id = spi_get_device_id(spi);
-
- info = (void *)id->driver_data;
+ if (plat_id)
+ id = plat_id;
+ else
+ dev_warn(&spi->dev, "unrecognized id %s\n", data->type);
}
- if (!info)
- return -ENODEV;
+ info = (void *)id->driver_data;
+
+ if (info->jedec_id) {
+ const struct spi_device_id *jid;
+
+ jid = jedec_probe(spi);
+ if (!jid) {
+ dev_info(&spi->dev, "non-JEDEC variant of %s\n",
+ id->name);
+ } else if (jid != id) {
+ /*
+ * JEDEC knows better, so overwrite platform ID. We
+ * can't trust partitions any longer, but we'll let
+ * mtd apply them anyway, since some partitions may be
+ * marked read-only, and we don't want to lose that
+ * information, even if it's not 100% accurate.
+ */
+ dev_warn(&spi->dev, "found %s, expected %s\n",
+ jid->name, id->name);
+ id = jid;
+ info = (void *)jid->driver_data;
+ }
+ }
flash = kzalloc(sizeof *flash, GFP_KERNEL);
if (!flash)